This application claims the priority of Korean Patent Application No. 2004-71221, filed on Sep. 7, 2004, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to a semiconductor probe with a resistive tip and a method of fabricating the same, and more particularly, to a semiconductor probe with a resistive tip having a semi-quadrangular pyramidal shape, and a method of fabricating the semiconductor probe.
2. Description of the Related Art
As compact products such as mobile communication terminals and electronic pocket notes have become more popular, the demand for highly-integrated nonvolatile micro recording media has increased. It is difficult to further miniaturize existing hard disks or to highly integrate flash memories. Therefore, information storage devices using scanning probe microscopy have been studied as an alternative.
Probes are used in various scanning probe microscopy (SPM) techniques. For example, probes are used for a scanning tunneling microscope (STM) that detects current produced when a voltage is applied between a probe and a sample to reproduce information, an atomic force microscope (AFM) that uses an atomic force between a probe and a sample, a magnetic force microscope (MFM) that uses an interactive force between a magnetic field produced by a sample and a magnetized probe, a scanning near-field optical microscope (SNOM) that overcomes a resolution limitation due to the wavelength of visible light, and an electrostatic force microscope (EFM) that uses an electrostatic force between a sample and a probe.
In order to record and reproduce information at high speed and high density using such SPM techniques, a surface charge in a small area of several tens of nanometers in diameter should be detected. Also, cantilevers should be in the form of an array to increase recording and reproduction speeds.
FIG. 1 is a schematic cross-sectional view of a conventional semiconductor probe disclosed in International Patent Publication No. WO 03/096409.
The semiconductor probe includes a cantilever 10 and a tip 12 formed near one end of the cantilever 10. The tip 12 includes a resistive region and electrode regions formed on both sides of the resistive region. In general, when a physical quantity is measured using the probe, the cantilever 10 is inclined at an angle of about 15 degrees when functioning. When the cantilever 10 is tilted at an angle of θ relative to a substrate 14 contacting the probe, the height of the tip 12 is H, the distance between the tip 12 and an end 11 of the cantilever 10 is D, and the gap G between the end 11 of the cantilever 10 and the substrate 14 contacting the probe is given by Equation 1.G=H×cos θ−D×sin θ  (1)
When information on a substrate is measured using a resistive tip, a semiconductor probe with a tip having a small height has the following advantages. First, the resistance of the electrode regions decreases, series resistance decreases, and sensitivity increases. Second, a second ion implantation process carried out to reduce the resistance of the electrode regions can be omitted. However, in the conventional probe, the distance D between the end 11 of the cantilever 10 and the tip 12 is considered to make up for an alignment error between the tip 12 and a cantilever mask. Accordingly, if the height of the tip 12 is reduced, the end 11 of the cantilever 10 may come close to the substrate 14 such that the end 11 of the cantilever 10, not the tip 12, first contacts the substrate 14. For example, when an alignment margin between the tip 12 and the end 11 of the cantilever 10 is 1 μm, if the height D of the tip 12 is less than 540 nm, the end 11 of the cantilever 10 contacts the substrate 14.